In the pharmaceutical industry, there are many pharmaceutical products which are difficult to manufacture into palatable dosage forms due to the intrinsic properties of the active ingredient. For example, many pharmaceutically active ingredients have properties which are such that in order to formulate a single dose, large quantities must be used. Accordingly, either multiple doses must be taken or single dose forms are large in size making them difficult to swallow. Additionally, many pharmaceutically active compounds are unpleasant tasting which, in turn, limits the forms in which they can be produced to alleviate this property.
Phosphorous binders bind phosphorus in the form of a phosphorous ion within the stomach and intestines and are useful in the treatment of patients with chronic renal disease. This process is thought to result from a chemical reaction between dietary phosphorus and the cation present in the binder compound. The reaction causes the formation of insoluble and hence unabsorbable phosphate compounds. The cation in some phosphorous binders is aluminum or calcium. Despite their capacity for binding phosphorous, large quantities of antacids must be ingested over a long period of time for them to be effective. Therefore, dosage size and palatability are particularly important for patients with chronic renal disease.
Calcium acetate is a particularly effective medication which is commonly used in the treatment of chronic renal failure, or hyperphosphatemia. Calcium acetate binds phosphorus in the gastrointestinal tract and reduces the percentage of consumed phosphorus which is absorbed into the bloodstream. Calcium acetate is particularly effective in reducing phosphorous absorption when it is administered relatively close in time to food consumption. Calcium acetate is typically administered orally. However, one common drawback to conventional calcium acetate formulations is that calcium acetate, like many other antacids, has an unpleasant, chalky taste.
Calcium acetate had been traditionally formulated as tablets. However, the tablet form of calcium acetate does little to enhance the palatability of the active compound. Attempts to address this concern include encapsulation of caplets of the calcium acetate as disclosed in U.S. Pat Nos. 6,576,665 and 6,875,445. These patents also relate to a specific useful bulk density of the calcium acetate as being from 0.55-0.75 g/cc.
Current calcium acetate formulations on the market include PHOSLO Gelcaps which comprise a 667 mg dose of calcium acetate manufactured as caplets placed inside a capsule shell (Size 0). However, the process which is used to generate the encapsulated caplets involves both a tablet forming step to formulate the caplet and special equipment to encase the caplet in an outer capsule. Accordingly, a simplified, more efficient process, compared to the process for producing the encapsulated caplet formulation, which produces a calcium acetate product that provides an effective dose of the active product without the unpleasant taste associated with the calcium acetate active substance, would be desirable.